1. Field of the Invention
The present invention relates to irrigation sprinkler heads and, more particularly, to a pop-up style sprinkler head having an integral device for indicating the position and facilitating the repair of the sprinkler head if it is damaged.
2. Description of the Background
Underground lawn irrigation systems commonly comprise a network of buried pipes connected at regular intervals to sprinkler heads. The RAINBIRD(trademark) SP40 series pop-up spray head manufactured by Rain Bird Mfg. Corp., 145 N. Grand Ave., Glenboro, Calif., 91741 is an exemplary pop-up style sprinkler head representative of the prior art.
FIG. 1 illustrates a pop-up style sprinkler head connected to an underground irrigation system. The sprinkler head 102 extends upwardly from an elbow or xe2x80x9cTxe2x80x9d joint 104, and only the uppermost portion of head 102 is exposed beyond the surface of the ground. Sprinkler head 102 typically comprises a cylindrical housing 107 containing an internal pop-up riser 112 capped by a nozzle 108. Nozzle 108 emits a spray when actuated by water pressure, and the spray pattern is fixed as determined by the type of nozzle 108 attached to riser 112.
At the end of an irrigation cycle, the water pressure shuts off, and an internal spring mechanism retracts the riser 112 back into housing 107 of the sprinkler head. The retracted nozzle lies flush at ground level and is protected from damage by lawn mowers, power trimmers, foot traffic or other ground level hazards which could dislodge the nozzle 108 from riser 112. It is not uncommon for grass or foliage to overgrow the sprinkler head thereby obscuring it from view in the retracted position.
During the course of normal use it is also not uncommon for grit or debris to fall into the sprinkler head 102. An accumulation of this foreign matter prevents the riser from fully retracting, leaving riser 112 extended from housing 107, and exposing nozzle 108 above the surface of the ground. A pass with a lawn mower can easily dislodge the exposed nozzle 108 from riser 112, thereby damaging the sprinkler head 102. The damaged riser thereafter will not be affected by the application or removal of water pressure.
Alternatively, nozzle 108 may simply become dislodged due to pedestrian traffic or unscrewed from riser 112 rendering sprinkler head 102 defective. Damaged or defective sprinkler heads are difficult to locate, either because they become entirely submerged in large pools of water, or because grass obscures the location of sprinkler head 102 when the riser is in the complete or partially retracted position.
If nozzle 108 is dislodged from sprinkler head 102, an uncontrolled geyser gushes from the sprinkler head during subsequent irrigation cycles. This has several adverse consequences. First, it results in flooding of one area of the lawn, which damages turf and promotes disease. Second, under-watering of adjacent areas of the lawn usually occurs as a result of decreased water pressure to the downstream sprinkler heads. Also, the geyser unnecessarily wastes water during the irrigation cycle, and depending on the location and time of day, geysers may go undetected for extended periods of time.
Replacing the defective sprinkler head with an entirely new sprinkler head remedies the geyser problem. However, even after the geyser is observed locating the damaged sprinkler head once the sprinkler shuts-off is difficult because of the flooding or natural overgrowth problems discussed above. Moreover, once the defective sprinkler head is found, making the a repair entails digging-up the damaged sprinkler head. This requires undue expense and effort and damages the lawn in the area of the repair.
Alternatively, the defective sprinkler head can be repaired by replacing the missing nozzle. However, this simple remedy is complicated by the fact that, in its retracted position, the riser 112 is not easily accessible inside the narrow body of sprinkler head 102. The force from a retracting spring (not shown) must be overcome to lift riser 112 from housing 107, and the narrow cylinder of sprinkler head 102 does not easily permit one to grasp riser 112. Without a device to withdraw the retracted riser 112, the threads on the riser remain inaccessible, and a new nozzle cannot be attached without disassembling the complete sprinkler head which in turn usually requires excavating around the unit.
Few devices in the prior art have addressed the problem of signaling the position of a damaged sprinkler head. U.S. Pat. No. 5,524,824 to Frimmer teaches a shut-off valve for use in a sprinkler head. The shut-off valve is positioned in the riser of the sprinkler head. A short perforated tube extends from the valve, and is spring biased against the underside of the sprinkler head nozzle. If the nozzle is dislodged, the shut-off valve is immediately forced upwardly where it engages a valve seat and prevents the flow of water from the head. The tube extending through the top of the sprinkler head also immediately signals that the sprinkler head is damaged.
Unfortunately, the Frimmer ""824 signaling device is a short fixed tube which becomes susceptible to damage from the same causal sources (rotary mowers, foot traffic or other ground hazards) because it deploys an instant after the nozzle is dislodged. It is highly likely in the case of the lawn mower inflicted damage that the mower would immediately truncate the signaling device negating its intended purpose. Therefore, it would be advantageous to have a sprinkler head with an integral apparatus for indicating the location of the damaged or defective sprinkler head (and facilitating its repair) that would deploy only when the nozzle is dislodged and water pressure is applied.
It is, therefore, an object of the present invention to provide a lawn irrigation sprinkler head incorporating a signaling device to indicate the position of the lawn sprinkler head if/when damaged.
It is another object of the present invention to enable the signaling device to facilitate the repair of the damaged head by providing a means to extract the riser from the inside of the damaged sprinkler head in order to replace a missing nozzle.
It is still further an object of the present invention to provide an integral shut-off valve on the alert and retrieval device to prevent the uncontrolled flow of water from a damaged sprinkler head during an irrigation cycle.
According to the present invention, the above-described and other objects are accomplished by providing a pop-up style lawn sprinkler head comprising an internal signaling and riser retrieval apparatus. The sprinkler head comprises a hollow, generally cylindrical housing threaded on the lower end for attachment to an elbow or xe2x80x9cTxe2x80x9d fitting on an irrigation pipe. The housing comprises an internal central channel occupied by a riser. A nozzle seals the top of the sprinkler head assembly when the riser is fully retracted in the housing.
The signaling and retrieval mechanism is a brightly colored, multi-stage telescoping element which resides in the central cavity of the riser. Under normal operating conditions, the device accompanies the riser as it is forced upwardly from the sprinkler head body by water pressure during a normal irrigation cycle. Water flows through the riser around the device and out the nozzle. In an undamaged sprinkler head, the upward telescoping movement of the device is limited by the nozzle. However, if the nozzle is dislodged, the water pressure causes the telescoping elements of the device to extend upwardly. When the irrigation cycle is complete, the self-latching device remains visible projecting from the top of the damaged sprinkler head.
Projecting from the sprinkler head, the brightly colored device signals the location of the damaged head, and is used to facilitate the replacement of the missing nozzle. Pulling upwardly on the device lifts the riser from the sprinkler head housing. This exposes the threads on the top of the riser, and enables a repair to be made by simply (1) holding the riser with one hand and pushing the telescoping device down within the riser and (2) screwing a replacement nozzle onto the riser. The riser retrieval feature of the signaling apparatus simplifies the repair process, and eliminates the labor intensive and aesthetically unpleasing task of digging up the entire sprinkler head.
In an alternative embodiment, the signaling and retrieval mechanism is a multi-stage telescoping element whose base, near the bottom of the riser also acts as a shut off valve. The base, which is spoked to allow the free flow of water when in the xe2x80x9cdownxe2x80x9d position, is spring biased to the xe2x80x9cupxe2x80x9d position. The shut off valve is prevented from closing during normal irrigation cycles by the top of the telescoping device which is held down by the nozzle (and filter basket). Again, during normal operation, the device rides up and down with the riser and due to its flow-through characteristics does not affect normal sprinkling.
In a scenario that is all too familiar, the riser, following an irrigation cycle, fails to retract into the sprinkler (due to grit or debris). Subsequent to this a lawn mower (logically being used when the irrigation system is not operating) passes over the riser and in so doing dislodges the nozzle. Due to being hit, the riser may or may not retract within the sprinkler head.
Immediately, the spring loaded shut off valve moves up within the riser to a valve seat located within the riser. The telescoping device does not extend because water pressure is not present. By not extending at this time the telescoping device does not expose itself to the same causal factors that precipitated the removal of the nozzle. During the next irrigation cycle, water pressure is applied and due to the position of the shut off valve no geyser appears and no water is wasted. However, the water pressure acts on the telescoping device extending it to its self latching position. At the end of the cycle the brightly colored telescoping device remains in the xe2x80x9cupxe2x80x9d position facilitating observation by concerned individuals. The retrieval/repair function of the telescoping device may then be used as described in the first embodiment.